Description:
High spatial resolution observations of the solar granulation up to 3 μm are possible on existing vacuum solar telescopes. They permit the analysis of the deepest photospheric layers near 1.7 μm. A high photometric accuracy is achieved using scanning techniques with a pinhole photometer; imaging methods are used for 2D-analysis. Statistically significant results on granulation, including power spectrum and histogram analysis, center-limb variations and lifetime analysis, are presented. Temperature fluctuations of periods near 5 minute are considered at 1.7 μm, as well as large-scale variations at the scale of the meso- and, especially, the super-granulation. We also discuss the “abnormal” granulation in magnetic regions and the umbral granulation in the cores of sunspots.